The present invention was conceived in the context of central tire inflation systems (CTIS). CTIS were originally developed for military applications, in particular off-road military wheeled trucks and trailers. However, CTIS are nowadays incorporated into non-military vehicles such as specialist construction, agricultural and commercial vehicles.
CTIS comprise one or more compressed air sources located on-board the vehicle in fluid communication with one or more tires. Tire pressure can therefore be adjusted by the CTIS. Typically, CTIS provide for delivery of compressed air to a tire through a hose connected to the wheel and in some cases, this is integrated into a vehicle axle. Accordingly, there are vehicle wheels and vehicle wheel assemblies designed to receive incoming flow of compressed air from the axle, and to deliver it to the tire.
U.S. Pat. No. 6,425,427 B1 discloses an on-axle tire inflation system.
US 2005/0236083 A1 discloses a vehicle wheel assembly comprising a rim secured to a wheel hub and a tire secured to the rim, with a hollow stud having an air conduit. The hollow stud extends through a rim opening and has a first end secured to the hub. A lug nut is secured to the hollow stud at a second end. The first end is operably connected to a source of compressed air through the air conduit. A central tire inflation valve is secured to the rim. The rim includes a first internal conduit communicating with the air conduit and the valve, and a second internal conduit communicating with the valve and the interior of the tire.
Drawbacks of the known systems include their adverse effect on wheel styling (which is not typically a concern with trucks but may not be aesthetically acceptable for passenger vehicles), their bulkiness and heaviness.
It is an object of the present invention to further improve on central tire inflation systems.